JP5450106B2 - In-vehicle antenna and method for transmitting and receiving signals - Google Patents

Description

  The present invention, in some embodiments, relates to an apparatus and method for a vehicle-mounted antenna, and more particularly, but not exclusively, to a method and apparatus for a vehicle-mounted antenna for satellite communications.

  There is a growing interest in realizing broadband communication systems on various forms of mobile platforms, such as marine ships and land vehicles. With a broadband satellite communication system having an antenna mounted on a vehicle, the antenna is used to help form a communication link with a geostationary space-based satellite. The antenna forms part of a communication terminal carried by the vehicle.

  Antennas with the ability to accurately track communication satellites from mobile platforms such as aircraft, ships and land vehicles, among other things, optimize data rates, improve downlink and uplink transmission efficiency and / or target This is necessary to prevent interference with satellites in orbit adjacent to the satellite. Such antennas allow mobile satellite communication platforms with relatively high attitude acceleration, such as aircraft and land vehicles, to receive and / or transmit signals from satellites such as geostationary satellites.

  In order to collect signals from remote sources and / or to transmit signals to them, it is necessary to keep the antenna pointing towards the satellite, taking into account the movement of the vehicle. In order to direct the antenna to the satellite, the vehicle-mounted antenna is tracked left and right (azimuth) and up and down (elevation). However, it should be noted that the in-vehicle antenna profile must be kept low in order to avoid disturbances due to smooth airflow on the vehicle or adverse effects on the vehicle's aesthetics.

  For example, International Patent Application Publication No. WO / 2008/015647, published February 7, 2008, is a double reflector offset mechanical pointing low profile telecommunications that is used, inter alia, in vehicles and also in high speed vehicles. The antenna is described. Its reduced physical dimensions facilitate its use over known solutions because it allows connection to a communications system such as a satellite through installation on a train or aircraft. The present invention resides in the field of telecommunications, and in the field of application of reduced size fixed, movable antennas, and thus in general telecommunications. The original double reflector antenna is derived from a second order polynomial that forms it in Cartesian space XYZ.

  An aspect of some embodiments of the present invention provides an antenna for communicating with a satellite from a moving vehicle. The antenna comprises a transmitter for generating a transmission signal, a main and a sub-reflector, and a waveguide associated with the transmitter for conducting the transmission signal to the sub-reflector. The sub-reflector is configured to redirect the transmitted signal in the direction of the main reflector, and the main reflector is configured to emit the redirected transmitted signal as an antenna beam in the direction of the satellite.

  Optionally, the waveguide has a bent path.

  Further optionally, the bent passage has a bending angle of at least 5 degrees.

  Optionally, the waveguide has a feed horn connected to its end, the waveguide being configured to conduct the transmitted signal through the feed horn toward the sub-reflector.

  Further optionally, the main reflector is arranged between the transmitter and the feed horn.

  Optionally, the transmitter is connected to the polarization element and the waveguide is used to guide the transmission signal between the polarization element and the feed horn.

  Optionally, the antenna further comprises a calibration track configured to calibrate the antenna beam by adjusting the position of the waveguide relative to the sub-reflector.

  Further optionally, the polarization element is a rotating orthomode transducer (OMT) configured to provide an association between the transmitter, receiver and waveguide, wherein the OMT is for polarizing the transmitted signal. And is configured to rotate about the central axis of the waveguide.

  Further optionally, the rotating OMT allows non-orthogonal assembly of the transmitted signal and the satellite signal received via the waveguide.

  Further optionally, the waveguide placement relative to the main and sub-reflectors is fixed during rotation.

  More optionally, the antenna further comprises first and second rotary joints, wherein the first rotary joint is disposed between the OMT and the waveguide, and the second rotary joint includes the OMT and the down converter, the transmitter, And at least one of the low noise block (LNB) downconverters.

  Further optionally, at least one of the first and second rotary joints is less than 1 centimeter in length.

  Further optionally, the first and second rotary joints are provided for the polarization elements around the central axis of the waveguide while maintaining the waveguide securely fixed with respect to the main and sub-reflectors. By promoting rolling, it is possible to adjust the polarization of the transmission signal.

  Optionally, the antenna further comprises an actuating unit configured to adjust the tilt angle of the main reflector in order to maintain a line of sight between the moving vehicle and the satellite.

  Optionally, the actuation unit is configured to adjust the tilt angle during travel of the moving vehicle.

  More optionally, the antenna further comprises a rotating base for supporting main and sub-reflectors and waveguides on the moving vehicle, and the actuating unit maintains a line of sight between the moving vehicle and the satellite. In addition, the rotation angle of the rotation base is configured to be adjusted.

  An aspect of some embodiments of the present invention provides an antenna for communicating with a satellite from a moving vehicle. The antenna emits a transmission signal, a rotary base configured to be attached to a moving vehicle, a main reflector configured to be tilted about a tilt axis located close to a lower portion of the main reflector, and And a sub-reflector configured to redirect the transmitted signal in the direction of the main reflector, wherein the main reflector emits the redirected transmitted signal as an antenna beam in the direction of the satellite Composed. Tilt allows the line of sight between the main reflector and the satellite to be maintained while the moving vehicle is traveling.

  Optionally, the feed and sub-reflector remain substantially stationary relative to the rotating base during tilting.

  Optionally, the antenna beam has a main lobe and tilting allows tilting of the center of the main lobe in the range of at least 50 degrees relative to the rotating base without gain degradation of more than 2 decibels.

  Further optionally, tilting allows tilting of the center of the main lobe in a range of at least 60 degrees.

  Optionally, tilting is performed by at least one support element, and the main reflector and at least one support element are detachably connected.

  Further optionally, the range is between tilt angles greater than 15 degrees relative to the rotating base.

  Optionally, the antenna further comprises a radome having a substantially flat top to cover the main and sub-reflectors.

  Optionally, at least one of the secondary and main reflectors has a substantially elliptical internal reflection surface profile.

  Optionally, the feed is configured to emit a substantially elliptical cone beam to the sub-reflector to form an elliptical radiation spot on the sub-reflector.

  Further optionally, the sub-reflector is configured to redirect the elliptical radiation spot in the direction of the main reflector to form an additional elliptical radiation spot therein, wherein the additional elliptical radiation spot width-to-height ratio. Is higher than the width-height ratio of the elliptical radiation spot.

  Optionally, the elliptical radiation spot has a width-to-height ratio of at least 1.6: 1.

  Further optionally, the additional elliptical radiation spot is at least 4: 1.

  Optionally, the feed has a pair of opposing ends for forming a substantially elliptical cone beam.

  Further optionally, the antenna lobe has a gain selected from the group consisting of at least 30 decibel isotropic (dBi) at 14 GHz and at least 25 decibel isotropic (dBi) at 11 GHz.

  Optionally, the antenna further comprises a transmitter configured to emit a transmission signal and a waveguide for conducting the transmission signal to the feed.

  An aspect of some embodiments of the invention provides a method for transmitting a transmission signal to a satellite. The method includes providing a transmit signal, polarizing the transmit signal, using a waveguide to conduct the polarized transmit signal toward the sub-reflector, Turning the wave transmission signal in the direction of the main reflector and launching it as an antenna beam towards the satellite.

  An aspect of some embodiments of the invention provides a method for receiving a communication signal from a satellite. The method includes tilting a main reflector of an antenna attached to a vehicle to enable reception of a communication signal while the vehicle is traveling, and communicating in the direction of a sub-reflector disposed in front of the waveguide. Redirecting the signal, using the waveguide to redirect the redirected communication signal from the sub-reflector toward the polarization element, and traveling with the directed reflection polarized And receiving a communication signal from a satellite.

  Unless defined otherwise, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

  Performing the method and / or system of embodiments of the present invention includes performing or completing selected tasks manually, automatically, or a combination thereof. Further, depending on the actual equipment and apparatus of the apparatus, method and / or system embodiments of the present invention, any number of selected steps can be performed by hardware, software, or firmware, or a combination thereof using an operating system. .

  For example, hardware for performing selected tasks according to embodiments of the present invention can be implemented as a chip or a circuit. As software, tasks selected according to embodiments of the present invention can be implemented as software, such as multiple software instructions that a computer executes using a suitable operating system. In an exemplary embodiment of the invention, one or more tasks according to exemplary embodiments of the methods and / or systems described herein are performed on a data processor, eg, a computing platform that executes multiple instructions. . Optionally, the data processor may be a volatile memory for storing instructions and / or data, and / or a non-volatile storage device for storing instructions and / or data (eg, a magnetic hard disk, and / or Removable recording medium). Optionally, a network connection is further provided. A display and / or user input device (eg, keyboard or mouse) is optionally further provided.

Several embodiments of the present invention are merely illustrated herein and described with reference to the accompanying drawings. With particular reference to the drawings in particular, it is emphasized that the details shown are only intended to illustrate the embodiments of the invention by way of example. In this regard, the manner in which embodiments of the present invention are implemented will become apparent to those skilled in the art from the description given with reference to the drawings.
FIG. 1 is a schematic diagram of an in-vehicle antenna for communicating with a communication system such as a satellite, according to some embodiments of the present invention. 2 is a schematic diagram of an exemplary set of reflectors for the in-vehicle antenna of FIG. 1 according to some embodiments of the present invention. FIG. 3 is a schematic view of electromagnetic radiation emitted from a waveguide feed toward a sub-reflector and redirected in the direction of the main reflector, according to some embodiments of the present invention. 4A is a schematic diagram of an in-vehicle antenna according to some embodiments of the present invention, and FIG. 4B is an enlarged schematic diagram of the corrugated horn depicted in FIG. 4A according to some embodiments of the present invention. is there. FIG. 4C is a graph representing antenna gain as a function of tilt angle in the range of 50 degrees. FIG. 5 is a schematic diagram of the exemplary waveguide feed depicted in FIG. 4A, according to some embodiments of the present invention. FIG. 6 is a schematic diagram illustrating a connection between a rotating OMT of an exemplary RF signal processing unit and the waveguide feed of FIG. 4A, according to some embodiments of the present invention. FIG. 7 is a schematic cross-sectional view of the connection of FIG. FIG. 8 is a schematic diagram of components of the waveguide feed and exemplary RF signal processing unit of FIG. 4A, according to some embodiments of the present invention. FIG. 9 is a schematic view of a tilt support mechanism for tilting the main reflector of the in-vehicle antenna according to some embodiments of the present invention. FIG. 10 is a schematic view of a vehicle to which an in-vehicle antenna 100 according to some embodiments of the present invention is attached. FIG. 11 is a schematic view of a vehicle to which an in-vehicle antenna 100 according to another embodiment of the present invention is attached. FIG. 12 is a schematic diagram of a method for transmitting a transmission signal to a satellite according to some embodiments of the present invention. FIG. 13 is a schematic diagram of a method for receiving a communication signal from a satellite according to some embodiments of the present invention.

  The present invention, in some embodiments, relates to an apparatus and method for a vehicle-mounted antenna, and more particularly, but not exclusively, to a method and apparatus for a vehicle-mounted antenna for satellite communications.

  Some embodiments of the present invention provide an antenna, such as a double reflector antenna, for communicating with a satellite from a moving vehicle. An antenna, sometimes referred to herein as an in-vehicle antenna, is a transmitter for generating transmission signals and / or receivers for receiving and decoding signals, main and sub-reflectors, feed horns, and transmission signals. It comprises a waveguide designed to conduct and return to the sub-reflector. The transmitter is optionally connected to a polarization element attached to the back of the main reflector to allow polarization of the transmitted signal. The sub-reflector turns the transmission signal in the direction of the main reflector, and the main reflector emits the redirected transmission signal in the direction of the satellite as an antenna beam. Since the waveguide is used to conduct the transmitted signal towards the sub-reflector rather than to other connecting cables such as coaxial transmission lines, both the transmitter and polarization element are as described further below. The rear of the main reflector can be arranged to increase the effective reflection space of the antenna.

  Some embodiments of the present invention comprise a rotating base designed to be attached to a moving vehicle and a main reflector that can be tilted about a tilt axis located proximate to the lower portion of the main reflector. An antenna for communicating with a satellite from a mobile vehicle is also provided. The antenna further comprises a feed for emitting a transmission signal and a sub-reflector for turning the transmission signal in the direction of the main reflector, the main reflector directing the redirected transmission signal to the satellite as an antenna beam. And fire. Optionally, the main reflector is designed to tilt while the feed and reflector remain substantially stationary relative to the rotating base. The tilting of the main reflector makes it possible to maintain a line of sight between the main reflector and the satellite while the mobile vehicle is traveling. The tilt axis of the main reflector allows for the generation of a low vertical profile vehicle-mounted antenna, for example as further described below.

  The antenna design allows reception and transmission of communication signals. Therefore, for the sake of brevity, in some parts of the description, only the transition logic between reception and transmission of communication signals is described. Before describing at least one embodiment of the present invention in detail, the present invention is not necessarily limited in its application to the components and / or methods described in the following description and / or shown in the drawings and / or examples. It should be understood that the details are not limited to the sequence details. The invention is capable of other embodiments or of being practiced or carried out in various ways.

  Reference is now made to FIG. 1, which is a schematic illustration of an in-vehicle antenna 100 for communicating with a telecommunication system such as a satellite (not shown), according to some embodiments of the present invention. The in-vehicle antenna 100 that is a double reflector antenna includes a main reflector 101 and a sub reflector 102 that face each other. Each of the reflectors 101, 102 is optionally as described further below and shown in FIG. 2, which is a schematic diagram of an exemplary set of reflectors 101, 102 according to some embodiments of the present invention. It has a reflective surface profile that is substantially elliptical. The onboard antenna 100 further comprises a transmission and / or reception unit 103 for generating and / or intercepting communication signals. As used herein, a communication signal is a transmission signal, a satellite signal, and / or any communication system signal received by the onboard antenna 100, and a transmission and / or reception unit 103 is a radio frequency (RF) transmitter. , RF receiver, polarization element, transceiver, and / or any combination thereof. Optionally, as shown in FIG. 1, the transmit and / or receive unit 103 is located at the rear of the main reflector 101. In such a manner, the space between the sub-reflector 102 and the main reflector 101 does not include any components or subordinate parts of the transmitting and / or receiving unit 103. In such a manner, as described further below, the efficiency of transmission and reception of communication signals is improved.

  For the sake of clarity, the reflective surface profiles of the secondary and primary reflectors 101, 102 are generally similar to geometric optics (GO) processes and / or physical optics (PO) processes for shaping reflective surfaces for antennas. Molded in a known process (Brown, KW et al., "A systematic design-in-the-design-in-the-class-for-the-quantity-off-and-the-quantity-off-and-the-anti-sense-and-the-anti-the-sense"). S. Digest Volume, Issue, 28 Jun-2 Jul 1993 Page (s): 772-775 vol.2). These processes are generally well known in the art and are therefore not detailed further herein.

  In some embodiments of the invention, the transmit and / or receive unit 103 includes an orthomode transducer (OMT) that couples and / or separates two RF signal paths. Optionally, the OMT is for coupling and / or separation between the uplink and downlink signal paths, for example, optionally transmitted in the same waveguide 107 as further described below. used. The OMT, sometimes referred to as an OMT / polarizer, supports polarization of communication signals transmitted and / or transmitted from and / or received by the transmitting and / or receiving unit 103. OMT supports circular polarization, such as left-hand and right-hand polarization, and / or linear polarization, such as horizontal and vertical polarization.

  The onboard antenna 100 further includes a waveguide 107, sometimes referred to herein as a waveguide 107. The waveguide 107 has a rear end and front ends 112, 113. The rear end 112 allows the transmission signal generated by the transmitting and / or receiving unit 103 to be emitted towards the sub-reflector 102, optionally via the front end 13 connected to the feed horn 108. As such, it is associated with a component of the transmitting and / or receiving unit 103.

  Optionally, the transmitted signal is transmitted using sub- and primary reflectors 102, 101 having a reflective surface profile as described below and having a gain greater than 30 decibel isotropic (dBi) at 14 GHz or greater than 25 dBi at 11 GHz. Is done. The subreflector 102 redirects the emitted radiation in the direction of the main reflector 101, which directs the radiation as an antenna beam, optionally to a telecommunication system that is a satellite, for example a geostationary satellite (GEO satellite). And fire.

  Optionally, the in-vehicle antenna 100 further includes trains, automobiles, trucks, buses, boats, ships, aircraft, helicopters, hovercraft, shuttles, and any other transport that transports people and / or things. A pedestal 105 for mounting on a vehicle (not shown) is provided. The pedestal 105 is optionally connected to a reflector base 101 that allows rotation of the reflectors 101, 102, the waveguide 107, and the transmit and / or receive unit 103, or portions thereof.

  Optionally, the main reflector 101 is connected to one or more support elements 104 that allow its tilt about a tilt axis 109 that is parallel to the rotating base 106, for example as shown at 110. In such a manner, the rotating base 106 is used to rotate the reflectors 101, 102, the waveguide 107, and the transmitting and / or receiving unit 103 at the same time, and the support element 104 is mainly connected to the rotating base 106. Used to tilt only the reflector 101. Optionally, the rotation base 106 is designed to allow continuous rotation. In such a manner, the rotation base 106 can adjust the rotation angles of the reflectors 101, 102, the waveguide 107, and the transmission and / or reception unit 103 by the fastest rotation operation.

  Optionally, the edge portion of the main reflector 101 is placed close to its tilt axis, for example as shown in FIG. In such a manner, the vertical profile 111 of the in-vehicle antenna 100 is kept relatively low while the main reflector 101 is tilted. Note that the vertical profile 111 is kept relatively low because the waveguide 107 optionally does not tilt with the main reflector 101. Further, in such a manner, the main reflector 101 can be rotated to change the tilt angle of the main lobe of the antenna beam, while the waveguide 107 and / or the sub-reflector 102 is relative to the rotating base 106. And is almost stable or completely stable. FIG. 3 is a schematic diagram of electromagnetic radiation emitted from the feed 108 in the direction of the sub-reflector 102 and redirected in the direction of the main reflector 101. The figure shows a tilt close to the lower edge of the main reflector without changing and / or substantially changing the placement of the waveguide 107 and the feed 108 and / or the subreflector 102 relative to the rotating base 106. Fig. 3 represents three states of the main reflector illustrating how the tilt angle of the main lobe of the antenna beam can be varied by tilting the main reflector about the axis 109;

  It should be noted that because the in-vehicle antenna 100 uses the waveguide 107, several advantages are obtained over the general use of an in-vehicle antenna with a coaxial transmission line. For example, the waveguide 107 significantly reduces dielectric loss. Furthermore, by using the waveguide 107 instead of the coaxial transmission line, it is possible to arrange the polarization element inside the transmission and / or reception unit 103 at the rear of the main reflector. With commonly used antennas, the uplink signals transferred on the coaxial transmission line must be polarized before they are emitted in the direction of the sub-reflector. Similarly, intercepted downlink signals must be polarized before they can be transmitted on a coaxial transmission line. Therefore, in these antennas, the polarization element must be placed in front of the main reflector. Waveguide 107, designed to conduct polarized waves without substantial loss of power, allows the polarization element to be placed at the rear of the main reflector 101, with the polarization element being the primary and secondary. Reduce the need to place in the space between the reflectors. Such a shift increases the effective reflective surface profile of the reflector and reduces dielectric loss.

  Reference is now made to FIG. 4A, which is a schematic illustration of an in-vehicle antenna 100 according to some embodiments of the present invention. Although the components of the in-vehicle antenna 100 are as shown in FIG. 1, FIG. 4A represents the exemplary reflector, exemplary waveguide, feed, and exemplary transmission and / or reception unit 103 in more detail.

  As outlined above and illustrated in FIGS. 2 and 4, the main reflector 101 and / or sub-reflector 102 is elliptical. The elliptical shape enables the generation of a relatively low profile on-board antenna. Optionally, the vertical dimension of the main reflector is less than 240 millimeters, and the vertical dimension of the in-vehicle antenna 100 shown in FIG. 4A is less than 250 millimeters without the optional radome. As described further below, the optional elliptical shape of the reflector and the optional structure and optional operation of the waveguide 107 is such that the flat radome adds less than 5 millimeters to the total vertical dimension of the onboard antenna 100. Enable assembly. Note that the vertical dimensions of the reflectors 101, 102 allow for the creation of an in-vehicle antenna 100 with a diameter: height ratio exceeding 3.5: 1.

  In such an embodiment, the waveguide 107 is optionally designed to emit a substantially elliptical cone beam toward the sub-reflector 102 via the feed horn 108. The substantially elliptical cone beam produces an elliptical spot on the subreflector 102. The subreflector 102 redirects the beam in the direction of the main reflector 101, which then emits an elliptical antenna beam along with uplink data towards a communication system such as a GEO satellite. Note that the onboard antenna 100 may be used to communicate with a terrestrial communication system. In such embodiments, the onboard antenna 100 is attached to the bottom of a flying vehicle such as an aircraft or shuttle. A main reflector that is directed toward the communication system during travel of a vehicle equipped with an antenna may optionally be capable of receiving signals from a satellite, as further described below. The received signal is diverted towards the sub-reflector 102, which signals the feed horn 108, which optionally conducts the signal through the waveguide 107 to the receiver of the transmitting and / or receiving unit 103. Concentrate.

  Optionally, the ratio between the width and height of the elliptical spot formed in sub-reflector 102 is about 1.5: 1, 1.6: 1, 1.7: 1, 1.8: 1. Or more. The elliptical cone beam is turned in the direction of the main reflector 101 by the subreflector 102 to form an elliptical spot having a larger area and / or higher ellipticity. Optionally, the ratio between the elliptical spot width and height formed in the main reflector 101 is about 3.5: 1, 3.6: 1, 3.7: 1, 3.8: 1, 3 9: 1, 4: 1, 4.2: 1, 4.3: 1, 4.4: 1, 4.5: 1, 5: 1, 6: 1, and 8: 1. In such a way, the reflective surfaces of the reflectors 101, 102 are better utilized and the power loss during the transmission process is reduced. As detailed above, the in-vehicle antenna 100 may be used to receive signals from the communication system.

  Reshaping the emitted transmitted signal in two steps with both the feed and the sub-reflector allows the antenna beam to be shaped with a more efficient shaping process. The shape and size of the elliptical reflecting surface of the secondary and main reflectors 101, 102 and the shape and size of the elliptical spot of the secondary and primary reflectors 101, 102 do not lose and / or substantially lose radiated power. In addition, it is possible to utilize all and / or most of the elliptical reflecting surfaces of the reflectors 101 and 102.

  Furthermore, as detailed above, the main reflector 101 is designed to tilt to allow adjustment of the elevation angle of the main lobe of the antenna beam. Tilt is optionally performed while maintaining the waveguide 107 and sub-reflector 102 in place relative to the rotating base 106. The above-described structure of the in-vehicle antenna 100 allows the main reflector to be tilted to effective angles exceeding 50, 55, and 60 degrees. Optionally, the effective tilt angle is defined as the angle at which the main lobe gain of the antenna beam remains degraded within a range of less than 2 decibels. For the sake of clarity, the gain is expressed as a decibel gain of the in-vehicle antenna 100 with reference to the zero dB gain (dBi) of the free space isotropic radiator. For example, as shown in FIG. 4C, which is a graph representing antenna gain as a function of tilt angle within a range of 50 degrees, the gain degradation at the center of the main lobe is 1.90 db or less. Optionally, the tilt angle represented in FIG. 4C is centered on an angle of 45 degrees with respect to the rotation base 106.

  Optionally, as described above, the waveguide 107 is connected to the corrugated feed horn 108 at one end. Optionally, as shown in FIG. 4B, the horn includes a pair of corrugated plates that are optionally mounted diagonally to the central axis 115 of the waveguide 107 as shown in FIG. 4A. The corrugated plates 451 and 452 are attached so that their corrugated side surfaces face each other. Corrugated plates 451, 452 constrain only the top and bottom of the transmission perimeter and the transmitted signal is beamed to form a spot with a high width: height ratio. The corrugated pattern of the corrugated feed horn 108 directs the emitted signal so that all polarization can enter and exit the feed.

  Optionally, the height of the spot formed on the subreflector does not exceed or substantially does not exceed the length of the subreflector 102. Since the gap between the plates is not constrained by the feed horn 108, the width of the transmission radiated from the waveguide 107 is longer than its height. Such a feed horn 108 allows a substantially elliptical cone beam to be formed and an optional required height-width ratio elliptical spot to be formed on the sub-reflector 102. Direct the transmitted signal.

  Reference is now also made to FIG. 5, which is a schematic diagram of a waveguide 107 connected on one side to a corrugated feed horn 108 and on the other side to a transmitting and / or receiving unit 103, according to some embodiments of the present invention. It is. Optionally, the waveguide 107 is mounted perpendicular to the tilt axis of the main reflector 101, optionally proximate its lower central portion, for example as shown in FIG. 4A. In some embodiments of the invention, the waveguide 107 is bent in a manner that allows reducing the height of the onboard antenna 100 and / or increasing the effective reflective surface profile of the main reflector. . The bend allows the feed horn 108 to be mounted to face the sub-reflector while maintaining a substantial portion 301 of the waveguide 107 substantially parallel to the rotating base 106. Optionally, the waveguide 107 is designed to be positioned below and / or substantially below the main reflector 101. Such a bent waveguide 107 does not substantially increase the height of the vehicle-mounted antenna 100. Further, the profile of the waveguide 107 does not absorb and / or redirect communication signals that are diverted from and / or directed to the sub-reflector 102, and thus the effectiveness of the sub- and main reflectors 101, 102. Does not reduce the reflective surface profile. The lower the waveguide 107, the fewer communication signals redirected from the sub-reflector 102 that the waveguide absorbs and / or redirects, and thus the reduction in the effective reflector surface profile of the main reflector 101 is less. . Optionally, the waveguide is bent more than 5 degrees, for example 5, 5.5, 6, 7, 8, 9, 10, 11, and 12 degrees with respect to the central axis of the waveguide. Optionally, the bend is formed using a connector 303 that connects the two waveguide elements 301, 302 such that the desired angle is formed.

  Optionally, the main reflector optionally has a niche at the bottom, as shown at 250 in FIGS. The niche 250 allows the waveguide 107 to be positioned in the center of the lower part of the main reflector, perpendicular to its main surface.

  In some embodiments of the invention, the components of the transmit and / or receive unit 103 are attached to the back of the main reflector 101 as shown in FIG. 4A. In such a way, the components of the transmitting and / or receiving unit 103 do not absorb and / or redirect the communication signal redirected by the sub-reflector 102 in the direction of the main reflector 101 as described above. Optionally, the transmit and / or receive unit 103 includes a receiver, a transmitter, and / or a polarization element. In such embodiments, the transmit and / or receive unit 103 may include a wave duct component such as an OMT that couples and / or separates the two wave signal paths. One of the paths allows the communication signal to be emitted through the waveguide 107, optionally forming an uplink that is transmitted to the communication system as described above, and the other path is the received signal. The path is designed to be received via the waveguide 107 as a downlink, for example. An OMT, optionally an OMT / polarizer, ensures that the paths are orthogonally polarized with respect to each other. OMT may allow orthogonal shifts between the two signal paths, resulting in approximately 30 dB separation in the Ku-band and Ka-band radio frequency bands.

  Reference is now made to FIG. 4 and FIGS. 6 and 7, which are schematic and cross-sectional views, respectively, of the connection between the rotating OMT 401 and other components of the in-vehicle antenna 100, according to some embodiments of the present invention. FIG. One of the connections shown is a connection between the rotating OMT 401 and the exemplary transmitting and / or receiving unit 103. Another of the connections shown is a connection between waveguides 107. The OMT 401 has a rear connector 410, a side connector 411, and a front connector 412. As shown in FIGS. 6 and 7, the rotating OMT 401 is connected to the waveguide 107 using front and rear rotary joints 402, 403. The front rotary joint 402 is optionally stationary so as to allow the transfer of polarized transmit signals into the waveguide 107 and / or the transfer of intercepted signals from the waveguide 107. A mechanical seal between the waveguide 107 and the rotating OMT 401 is provided. The rear rotary joint 403 is a connector that is optionally stationary with respect to the rotating base 106 to allow transmission of communication signals into and / or out of the waveguide 107 via the rotating OMT 401. Provides a mechanical seal between 404 and rotating OMT 401. Optionally, the mechanical seal formed by each of the rotary joints 402, 403 is optionally around the end of the rotating OMT 401 and around the element connected to the rotating OMT 401 using springs and / or screws. Maintained by an annular polymer element 415, 416 attached to and pressed against. For example, the front rotary joint 402 includes an annular plastic element that surrounds and presses the waveguide 107 and front connector 412 to seal the space between them, as shown, for example, in FIG.

  As described above, the rotating OMT 401 is a polarization element and may be referred to herein as a rotating OMT / polarizer assembly 401. As described above, the rotating OMT / polarizer assembly 401 can optionally support circular and / or linear polarization in the Ku and Ka bands. The polarization is optionally adjusted by rotation of the rotating OMT / polarizer assembly 401. As described above, the rotating OMT 401 optionally rotates while the waveguide 107 and the connector 404 are stably maintained with respect to the rotating base 106. Furthermore, the polarization adjustment can be performed while the vehicle-mounted antenna 100 is moving, for example, as described below.

  Optionally, connector 404 is connected to a transmitter, such as a block upconverter (BUC), for transmitting uplink satellite signals via waveguide 107. The BUC converts a frequency band from a low frequency to a high frequency, for example, from an L band to a Ku band, a C band, and / or a Ka band. Optionally, the BUC power is up to 1600 watts.

  Referring now also to FIG. 8, it is a schematic diagram of a waveguide 107, a rotating OMT 401, an LNB converter 501, and a motion mechanism 502 for rotating the rotating OMT 401 and the LNB converter 501 according to some embodiments of the present invention. It is. Optionally, the side connector 411 is connected to the receiving unit, preferably via a down converter and / or a low noise block (LNB) down converter, for example as shown at 501. The LNB downconverter 501 receives relatively high frequency bands from the rotating OMT 401, amplifies them, and converts them into similar signals carried at a lower frequency, also known as the intermediate frequency (IF), In addition, the IF signal is designed to be transferred to a receiver such as a satellite receiver. Optionally, the LNB downconverter 501 rotates via a connection between the side connection 411 and optionally a filter 505 that is bent to form an L-shaped connection 419, for example as shown in FIG. It is attached to OMT401. The bending of the connector 419 reduces the rotation profile of the LNB down converter 501 and enables generation of a vehicle-mounted antenna with a smaller amount of rotation. In such an embodiment, the LNB downconverter 501 is designed to rotate with the rotating OMT 401 during the polarization adjustment described above. The LNB downconverter 501 is optionally connected directly and / or optionally via a relatively short connector as shown at 411 to the rotating OMT 401 so that communication signals transferred by the rotating OMT 401 can be transmitted. Power is not substantially reduced.

  Optionally, motion mechanism 502 includes a polarization motor drive 503, encoder 504, and lever 506, or rotation OMT 401, optionally for rotating about 180 degrees along a particular rotation angle. Includes any other mechanical assembly such as a gear for transmitting mechanical force from the drive 503 to the rotating OMT 401. The encoder 504 is optionally a central controller (not shown) designed to provide closed loop control over polarization to improve communication with the communication system by increasing the accuracy of the reception and / or transmission process. Connected). The encoder 504 is optionally an optical encoder such as AVAGO Technologies ™ HEDS 5500/5540, HEDS 5600/5640, and HEDM 5500/5600, the specifications of which are incorporated herein by reference.

  As described above, the waveguide 107 is optionally connected to the transmitting and / or receiving unit 103 via the rotating OMT 401. The combination of these components may be referred to herein as a transmission and / or receiving assembly.

  Optionally, the transmission and / or receiving assembly is connected to a calibration track, for example as shown in FIG. Calibration track 415 allows a technician to calibrate communication between in-vehicle antenna 100 and the communication system. The technician calibrates the communication by adjusting the distance between the feed horn 108 and the subreflector 102. The adjustment is performed by manipulating the position of the transmission and / or receiving assembly in the calibration track 415. Optionally, a calibration track 415 allows the transmission and / or receiving assembly to be manipulated in the front-rear direction along the central axis of the waveguide. As described above, the waveguide 107 is optionally bent. In such an embodiment, the calibration track 415 is such that the feed horn 108 is directed toward the sub-reflector 102, for example, along the axis of the waveguide element located between the connector 303 and the feed horn 108. And allowing operation of the transmission and / or receiving assembly. After the calibration process, the technician secures the transmission and / or receiving assembly to the calibration track 415 at a location that allows optimal or substantially optimal communication with the communication system.

  Reference is now made to FIGS. FIG. 9 is a schematic view of a tilt support mechanism 600 for tilting the main reflector 101 about the tilt axis 109 according to some embodiments of the present invention. As used herein, tilting means adjusting the angle of the main reflector 101 relative to the rotating base 106. The tilting support mechanism 600 includes two support levers 601 and 602 that are designed to be optionally detachably connected to the main reflector 101.

  Optionally, each of the support levers 601, 602 is designed to be connected to a different side of the main reflector 101. At least one of the support levers 601 and 602 is connected to a tilt drive 603 designed to operate the main reflector 101 about a tilt axis 109 parallel to the rotation base 106 as described above, for example. Optionally, the angle of the main reflector 101 is between 15 degrees and 80 degrees with respect to the rotating base 106. As described above, the waveguide 107 is designed to remain stable or substantially stable with respect to the rotating base 106 during angle adjustment of the main reflector 101. In such a manner, the in-vehicle antenna 100 can transmit an antenna beam whose main lobe center is directed at any angle between about 15 degrees and about 80 degrees with respect to the rotation base 106, but is optional. As described above, the low profile is maintained.

  Optionally, the angle of at least one of the support levers 601, 602 is monitored by an encoder 604, such as an optical encoder, eg, QPhase ™ QD787 20 mm (0.787 ″) Diameter Absolute Optical Encoder. The specification is incorporated herein by reference, optionally as outlined above and below, encoder 604 optionally tilts main reflector 101 according to the position of the communication system relative to vehicle antenna 100. In order to adjust the angle, it is connected to a central controller designed to control the tilt drive 603. The central controller is a communication system that is a reflective surface of the main reflector 101 and optionally a GEO satellite. Data from encoder 604 to maintain a line of sight between Used. Further, adjustment of the tilt angle of the main reflector 101, as optionally below, is performed during running of the vehicle-mounted antenna 100.

  Optionally, the main reflector 101 and each of the support levers 601, 602 are connected by a quick release mechanism such as a screw and / or nut fixation. In such a manner, the main reflector can be easily removed and / or assembled during assembly of the in-vehicle antenna 100 and / or during maintenance of the in-vehicle antenna 100. Optionally, the main reflector 101 can be replaced according to the geographical location where the in-vehicle antenna 100 intends to transmit and / or receive communication signals. In such an embodiment, when the in-vehicle antenna 100 moves from one geographic location to another, the main reflector can be easily replaced with a different reflector shape, and optionally, for example, Beam scans with different tilt ranges between 30 and 90 degrees can be performed.

  Optionally, as shown at 960, the in-vehicle antenna 100 includes a radome that allows electromagnetic signals that are relatively undamped between the in-vehicle antenna 100 and the communication system. Optionally, the radome structure has a flat top surface, for example as shown in FIG. The flat top surface reduces the influence of the in-vehicle antenna 100 on the interference with the in-vehicle antenna 100 and / or the aesthetics of the vehicle 950 due to the smooth airflow on the vehicle 950.

  Reference is again made to FIG. In some embodiments of the invention, the motor drive described above is controlled by a central controller. The central controller operates the motor drive described above so that the main reflector 101 can be tilted and optionally the rotation base 106 can be rotated in the direction of the communication system, which is a GEO satellite. Optionally, the central controller is designed to adjust the polarization of the communication signal to operate one of the motor drives described above to improve communication with the communication system. Optionally, the operation of the motor drive described above may include input from the encoder described above and / or position data related to the position and / or angle of the vehicle-mounted antenna 100 relative to the communication system and / or any combination thereof. Performed according to input from one or more measurement units used to measure. As used herein, a measurement unit is an accelerometer for measuring the angle of the vehicle on which the rotation base 106 and / or the vehicle-mounted antenna 100 is mounted, the vehicle-mounted antenna 100 and / or the current latitude of the vehicle described above. And / or a global positioning system (GPS) for determining longitude coordinates, and / or a compass for measuring the magnetic north for the vehicle-mounted antenna 100 and / or the current orientation of the vehicle described above.

  The orientation of the main reflector 101 allows communication signals to be transmitted to and / or received from the communication system. As is generally known, GEO satellites have a geosynchronous orbit, and their position on the orbit is fixed with respect to the earth. When the in-vehicle antenna 100 is attached to the moving vehicle, the central control device continuously directs the reflecting surface of the main reflector 102 toward the GEO geostationary satellite. In order to compensate for the movement of the vehicle, the central controller continuously measures the current angular position and translational position of the in-vehicle antenna 100, optionally by using one or more of the measurement units described above. This current angular position and translation position information, and optionally the current rotation, tilt, and / or polarization state, optionally obtained by one or more of the encoders described above, Can be used by the central controller to calculate an angle correction command that maintains the reflecting surface of the main reflector facing the satellite while the vehicle is mounted. The angle correction command is for adjusting one or more of the current tilt of the main reflector, the rotation of the rotating base 106 of the in-vehicle antenna 100, and / or the polarization of the emitted communication signal.

  In one embodiment of the present invention, the onboard antenna 100 uses a beacon decoder to measure the strength and optionally the quality of the beacon signal received via the waveguide 107. One example of such a beacon decoder is the Satelite Systems Corporation ™ Ku-band beacon tracking receiver P / N 3430-KuAZ000, the specification of which is incorporated herein by reference. The beacon decoder detects the strength of the received beacon signal, and the central controller accordingly adjusts the tilt of the main reflector, the rotation of the rotating base 106 of the in-vehicle antenna 100, and / or the polarization of the emitted communication signal and / or the received signal. A correction command for adjustment is calculated. In particular, the beacon decoder decodes the satellite beacon signal and continuously measures its strength and optionally quality. Optionally, the central controller operates the in-vehicle antenna 100 in a scan pattern, for example, a spiral scan pattern or a raster scan pattern, and measures the intensity of the satellite beacon signal during the scan. Such a measurement allows the central controller to direct the current tilt of the main reflector 101 and the rotation of the rotating base 106 of the in-vehicle antenna 100 to a position and orientation where the intensity and / or quality of the beacon signal is high. Furthermore, such a measurement allows the central controller to adjust the polarization of the emitted communication signal to achieve the same goal. In such a manner, reception of signals from the communication system and / or transmission of transmission signals to the communication system is improved.

  Reference is now made to FIG. 12, which is a schematic diagram of a method 910 for transmitting a transmission signal to a satellite, according to some embodiments of the present invention. Initially, as shown at 911, the transmitted signal is optionally provided by a transmitter, such as a block upconverter (BUC), optionally for transmitting an uplink satellite signal via a waveguide as described above. Is done. Next, as shown at 912, the transmitted signal is optionally polarized using an OMT / polarizer. Here, as shown at 913, the waveguide is used to conduct a polarization transmission signal, optionally through a feed horn, in the direction of the sub-reflector, for example as shown in FIG. As shown at 914, the emitted polarization transmission signal is optionally redirected by the sub-reflector in the direction of the main reflector, allowing the emitted polarization transmission to be launched toward the satellite as an antenna beam. To do. Method 910 can optionally be implemented using the vehicle-mounted antenna described above, as described above.

  Reference is now made to FIG. 13, which is a schematic diagram of a method 920 for receiving a communication signal from a satellite, according to some embodiments of the present invention. Initially, as shown at 921, the tilt angle of the main reflector of the in-vehicle antenna can be optionally received as described above so that a communication signal can be received from the satellite while the vehicle is attached to the antenna. Adjusted. The communication signal is then turned in the direction of the sub-reflector, as shown at 922. Here, as described above and shown at 923, the waveguide is used to direct the reflection of the redirected communication signal from the sub-reflector toward the polarization element. This allows for directed reflection polarization, as shown at 924. Polarization makes it possible to receive communication signals from satellites and optionally forward them to a receiver, for example via LNB as described above. The method 920 can optionally be implemented using the vehicle-mounted antenna described above as described above.

  The term “about” as used herein refers to ± 10%.

  The terms “comprises, comprising, includings, including”, “having”, and their equivalents mean “including, but not limited to, including”. .

  The term “consisting of” means “including and limited to”.

  The term “consisting essentially of” means that additional components, steps and / or parts do not substantially alter the basic and novel characteristics of the claimed composition, method or structure. Only that means that the composition, method or structure may comprise additional components, steps and / or moieties.

  As used herein, the singular forms ("a", "an", and "the") encompass multiple references unless the context clearly indicates otherwise. For example, the term “a compound” or the term “at least one compound” can encompass a plurality of compounds, including mixtures thereof.

  Throughout this disclosure, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, descriptions of ranges such as 1-6 are specifically disclosed subranges (eg, 1-3, 1-4, 1-5, 2-4, 2-6, 3-6 etc.), and Should be considered as having individual numerical values (eg, 1, 2, 3, 4, 5 and 6) within the range. This applies regardless of the breadth of the range.

  Whenever a numerical range is indicated in this document, it is meant to include any mentioned numerals (fractional or integer) included in the indicated range. The first indicated number and the second indicated number “the range is / between” and the first indicated number “from” to the second indicated number “to” The expression “range to / from” is used interchangeably and is meant to include the first indicated number, the second indicated number, and all fractions and integers in between.

  As used herein, the term “treating” is used to cancel, substantially inhibit, slow down, or reverse the progression of a condition, or to treat a clinical or aesthetic symptom of a condition. Including substantially improving or substantially preventing the appearance of clinical or aesthetic symptoms of the condition.

  It will be appreciated that certain features of the invention described in the context of separate embodiments for clarity may also be provided in combination in a single embodiment. Conversely, various features of the invention described in the context of a single embodiment for the sake of brevity are preferably provided separately or in appropriate subcombinations or in other embodiments of the invention. You can also. Certain features that are described in the context of various embodiments should not be considered essential features of those embodiments, unless that embodiment is inoperable without those elements. .

  While the invention has been described in conjunction with specific embodiments thereof, it will be apparent to those skilled in the art that there are many alternatives, modifications, and variations. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variations that fall within the broad scope of the appended claims.

  All publications, patents and patent applications mentioned in this document are hereby incorporated by reference in their entirety as if each individual publication, patent or patent application was specifically and individually cited. It is. Furthermore, citation or confirmation in this application should not be considered as a confession that it can be used as prior art to the present invention. To the extent that section headings are used, they should not necessarily be considered limiting.

Claims (23)

An antenna for communicating with a satellite from a moving vehicle,
A rotating base,
Main and sub reflectors,
A rotating orthomode transducer (OMT) provided behind the main reflector and configured to polarize the transmitted signal;
A waveguide associated with the OMT for conducting the polarized transmission signal toward a feed horn between the main reflector and the sub-reflector; and of the waveguide and the sub-reflector An actuating unit configured to adjust the tilt angle of the main reflector relative to the rotating base while at least one remains substantially stationary relative to the rotating base;
The feed horn radiates the sub-reflector with a substantially elliptical cone beam polarized for each of the polarized transmission signals to form an elliptical radiation spot on the sub-reflector. The sub-reflector is configured to redirect the elliptical cone beam in the direction of the main reflector to form an additional elliptical radiation spot therein, the main reflector configured to transmit the redirected transmitted signal; Configured to launch in the direction of the satellite as an antenna beam,
The polarization of the polarized transmission signal is rotated around the central axis of the waveguide while maintaining the waveguide securely fixed with respect to the main reflector and sub-reflector. An antenna that is adjusted by the rotation of the OMT.   The antenna of claim 1, wherein the waveguide has a bent path.   The antenna of claim 2, wherein the bend path has a bend angle of at least 5 degrees.   The OMT is configured to provide an association between a transmitter, a receiver, and the waveguide, and the OMT is rotated about a central axis of the waveguide to polarize the transmitted signal. The antenna according to claim 1, which is configured as follows.   The first rotary joint is further disposed between the OMT and the waveguide, and the second rotary joint includes the OMT and an up-converter, a transmitter, and a low-rotation joint. The antenna according to claim 4, arranged between at least one of the noise block (LNB) downconverters.   6. The antenna of claim 5, wherein at least one of the first and second rotary joints is less than 1 centimeter in length.   7. The actuation unit according to any of claims 1 to 6, wherein the actuation unit is configured to adjust the tilt angle to maintain a line of sight between the main reflector and a satellite during travel of a moving vehicle. antenna.   The rotating base is configured to support the main and sub-reflectors and the waveguide on a moving vehicle, and the actuating unit maintains a line of sight between the main reflector and a satellite, The antenna according to claim 1, wherein the antenna is configured to adjust a rotation angle of the rotation base. An antenna for communicating with a satellite from a moving vehicle,
A rotating base configured to be attached to a moving vehicle;
A main reflector configured to be tilted about a tilt axis located close to a lower portion of the main reflector and attached to the rotating base;
A feed horn for emitting the transmitted signal as an elliptical cone beam;
A sub-reflector configured to divert the elliptical cone beam toward the main reflector and attached to the rotating base;
An orthomode transducer (OMT) configured to polarize the transmitted signal;
A waveguide for conducting the polarized transmission signal in the direction of the feed horn,
The main reflector is configured to launch the elliptical cone beam in the direction of a satellite;
Before Ki楕 circle Kiribi over beam is polarized with respect to each of the polarized transmission signal,
The rotating base is configured to rotate the primary and secondary reflectors;
The tilting and rotation allows the line of sight between the main reflector and the satellite to be maintained while the mobile vehicle is traveling,
The feed horn and the sub-reflector remain substantially stationary with respect to the rotating base during the tilting;
The subreflector is configured the elliptical Kiribi over arm so as to form an additional oval radiation spots therein by turning in the direction of the main reflector,
The polarization of the polarized transmission signal is rotated around the central axis of the waveguide while maintaining the waveguide securely fixed with respect to the main reflector and sub-reflector. An antenna that is adjusted by the rotation of the OMT.   10. The elliptical cone beam has a main lobe and the tilt allows tilting of the center of the main lobe in a range of at least 50 degrees with respect to the rotating base without gain degradation of more than 2 decibels. Antenna described in.   11. An antenna according to claim 9 or 10, wherein the tilting is performed by at least one support element, the main reflector and the at least one support element being detachably connected.   At least one of the secondary and primary reflectors reflects a substantially elliptical cone beam having an elliptical spot having a width-to-height ratio of at least 3.5: 1 on the primary reflector. The antenna according to claim 9, having a size and a shape.   The antenna of any of claims 9-12, wherein the feed horn is configured to emit a substantially elliptical cone beam to the sub-reflector to form an elliptical radiation spot on the sub-reflector. . The antenna according to claim 13, wherein a width-height ratio of the additional elliptical radiation spot is higher than a width-height ratio of the elliptical radiation spot. The antenna of claim 13 , wherein the elliptical radiation spot has a width-to-height ratio of at least 1.6: 1 on the sub-reflector.   16. An antenna according to any of claims 9 to 15, wherein the additional elliptical radiation spot has a width-to-height ratio of at least 4: 1 on the main reflector.   17. The orthomode transducer (OMT) configured to conduct the transmission signal and a waveguide for conducting the transmission signal to the feed horn. antenna. A method for transmitting a signal to a satellite comprising:
Providing an antenna having main and sub-reflectors facing each other and an orthomode transducer (OMT), wherein the main reflector is disposed between the OMT and the sub-reflector on a rotating base;
Providing a transmission signal to the OMT;
Polarizing the transmitted signal by rotating the OMT about the central axis of the waveguide while maintaining the waveguide securely fixed with respect to the main reflector and the sub-reflector When,
Using the waveguide to conduct the polarized transmitted signal toward a feed horn;
Radiating the polarized transmission signal as an elliptical cone beam towards a sub-reflector;
Tilting the main reflector while at least one of the sub-reflector and the waveguide remains substantially stationary relative to the main reflector;
Turning the elliptical cone beam in the direction of the main reflector to form an additional elliptical radiation spot there and directing the elliptical cone beam towards the satellite. A method for receiving communication signals from a satellite, comprising:
Tilting a main reflector of an antenna attached to a rotating base installed on the vehicle to enable reception of communication signals while the vehicle is running;
Turning the communication signal as an elliptical cone beam in the direction of a sub-reflector placed in front of the waveguide;
Using the waveguide to direct an elliptical reflection of the redirected communication signal from the sub-reflector toward an orthomode transducer (OMT);
In order to enable reception of the communication signal from the satellite during the traveling, the waveguide is maintained in a state where the waveguide is securely fixed with respect to the main reflector and the sub-reflector. Polarizing the directed reflection by rotating the OMT about a central axis. A method for communicating through a satellite,
Generating a transmission signal for transmission by an antenna;
Polarizing the transmitted signal using an ortho-mode transducer (OMT);
A first elliptical spot having a width-to-height ratio of at least 1.6: 1 on a sub-reflector, emitting the polarized transmission signal through a feed horn and a waveguide to generate an elliptical cone beam The steps of creating
Tilting the main reflector of the antenna mounted on a rotating base;
Turning the elliptical cone beam in the direction of the main reflector to create a second elliptical spot on the main reflector having a width-to-height ratio of at least 3.5: 1;
Directing the elliptical cone beam as an antenna beam toward the satellite;
The polarization of the antenna beam is adjusted by rotating the OMT around the central axis of the waveguide while maintaining the waveguide securely fixed with respect to the main reflector and the sub-reflector. And a method comprising:   21. The method of claim 20, wherein the rotation is performed while maintaining the width-height ratio.   The method according to claim 20 or 21, wherein the polarization is selected from a plurality of polarizations between the L band and the Ku band and between the C band and the Ka band. An antenna for receiving a downlink signal from a satellite from a moving vehicle,
A rotating base,
Main and sub reflectors,
A waveguide;
A rotating orthomode transducer (OMT) provided behind the main reflector and configured to polarize a downlink signal by rotating relative to the waveguide, wherein the waveguide comprises the main reflector Associated with the OMT to conduct the downlink signal from a feed horn between a reflector and the sub-reflector;
Configured to adjust a tilt angle of the main reflector relative to the rotating base while at least one of the waveguide and the sub-reflector remains substantially stationary relative to the rotating base. An operating unit,
The feed horn is configured to receive the downlink signal as an elliptical cone beam via the subreflector, and the subreflector transmits the elliptical cone beam from the main reflector to the feedhorn. An antenna configured to turn and the main reflector configured to receive the downlink signal from a satellite.

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